As is well known, an optical image at least consists of light waves with different main wavelengths, such as blue, green and red light waves. Predetermined monochromatic light or polychromatic light is obtained mainly by exciting fluorescent powder with laser light or light sources such as an LED in the fields of lighting sources, projection display and the like, and such scheme usually utilizes the laser light or LED emergent light to enter a fluorescent powder color wheel rotating at a high speed to achieve effects of exciting colored light and dissipating heat.
The color wheel adopted in the prior art is generally a disc type color wheel. The diameter of the color wheel can't be too small in order to achieve the effect of exciting the colored light and meet the requirement on heat dissipation at the same time, and lead to that the thickness of a projector can't be reduced.